Serious mold problems may require professional removal services.
The Mississippi State Department of Health does not perform these services. Check your local Yellow Pages for suitable professional removal.

About Mold: General Information

What is mold?

Molds are simple, microscopic organisms, found virtually everywhere, indoors and outdoors. Molds can be found on
plants, foods, dry leaves, and other organic material. Molds are needed for breaking down dead material. Mold spores
are very tiny and lightweight, and this allows them to travel through the air. Mold growths can often be seen in the
form of discoloration, ranging from white to orange and from green to brown and black. When molds are present in large
quantities, they can cause allergic symptoms similar to those caused by plant pollen.

Should I be concerned about mold in my home?

Yes, if the contamination is extensive. When airborne mold spores are present in large numbers, they can cause
allergic reactions, asthma episodes, infections, and other respiratory problems for people. Exposure to high spore
levels can cause the development of an allergy to the mold. Mold can also cause structural damage to your home.
Similarly, when wood goes through a period of wetting, then drying, it can eventually warp and cause walls to crack or
become structurally weak.

What does mold need to grow?

For mold to grow, it needs:

food sources such as leaves, wood, paper, or dirt

a source of moisture

a place to grow

Can mold become a problem in my home?

Yes, if there is moisture available to allow mold to thrive and multiply. The following are sources of indoor
moisture that may cause problems:

flooding

backed-up sewers

leaky roofs

humidifiers

mud or ice dams

damp basement or crawl spaces

constant plumbing leaks

house plants — watering can generate large amounts of moisture

steam from cooking

shower/bath steam and leaks

wet clothes on indoor drying lines

clothes dryers vented indoors

combustion appliances (e.g. stoves) not exhausted to the outdoors

CAUTION: If you see moisture condensation
on the windows or walls, it is also possible that you have a combustion problem in your home. It is important to have
sufficient fresh air available for fuel burning appliances, such as the furnace, water heater, stove/range, clothes
dryer, or fireplace. A shortage of air for these appliances can result in back drafting of dangerous
gases such as carbon monoxide into the home. To prevent back drafting of air, you need either open vents or a
ventilation system that brings fresh air into the home to replace air that is exhausted out. Have your local
utility company or a professional heating contractor inspect your fuel-burning appliances annually.

Health Effects

How am I exposed to indoor molds?
Mold is found everywhere, indoors and outdoors. It is common to find mold spores in the air of
homes and growing on damp surfaces. Much of the mold found indoors comes from outdoor sources.
Therefore, everyone is exposed to some mold on a daily basis without evident harm. Mold spores
primarily cause health problems when they enter the air and are inhaled in large number. People
can also be exposed to mold through skin contact and eating.

How much mold can make me sick?
It depends. For some people, a relatively small number of mold spores can cause health
problems. For other people, it may take many more. The basic rule is, if you can see or smell
it, take steps to eliminate the excess moisture, and to cleanup and remove the mold.

Who is at greater risk when exposed to mold?
Exposure to mold is not healthy for anyone inside buildings. It is important to quickly
identify and correct any moisture sources before health problems develop. The following
individuals appear to be at higher risk for adverse health effects of molds:

Are some molds more hazardous?
Allergic persons vary in their sensitivities to mold, both as to amount and type needed to
cause reactions. In addition, certain types of molds can produce toxins,
called mycotoxins, that the mold uses to inhibit or prevent the growth of other
organisms. Mycotoxins are found in both living and dead mold spores. Materials permeated
with mold need to be removed, even after they are disinfected with cleaning solutions.
Allergic and toxic effects can remain in dead spores. Exposure to mycotoxins may present a
greater hazard than that of allergenic or irritative molds. Mycotoxins have been found in
homes, agricultural settings, food, and office buildings.

Detection

How can I tell if I have mold in my house?
If you can see mold, or if there is an earthy or musty odor, you can assume you have a mold
problem. Allergic individuals may experience the symptoms listed above. Look for previous water
damage. Visible mold growth is found underneath materials where water has damaged surfaces, or
behind walls. Look for discoloration and leaching from plaster.

Should I test my home for mold?
The Mississippi State Department of Health does not recommend testing as the first step to
determine if you have a mold problem. Reliable sampling for mold can be expensive, and requires
equipment not available to the general public. Residents of individual private homes must pay a
contractor to carry out such sampling, as it is not usually done by public health agencies.
Mold cleanup is usually considered one of the housekeeping tasks of the private citizen, along
with roof and plumbing repairs, sweeping and house cleaning. Another problem is that there are
few available standards for judging what is an acceptable quantity of mold. In all
locations, there is some outdoor levels of molds. If sampling is carried out, an outdoor air
sample needs to be taken at the same time as the sample indoors, to provide a baseline
measurement. Since the susceptibility of individuals varies so greatly, sampling is at best a
general guide. The simplest approach is: if you can see or smell mold, you have a
problem. Once you know the problem exists, follow the procedure given next. Unless the
source of moisture is removed and the contaminated area is cleaned and disinfected, mold growth
is likely to reoccur.

Clean-Up Procedures

Serious mold problems may require professional removal services.
The Mississippi State Department of Health does not perform these services. Check your local Yellow Pages for suitable professional removal.

If mold is a problem in your home, you need to clean up the mold and eliminate sources of
moisture.

Identify and correct the moisture source

Clean, disinfect, and dry the moldy area

Bag and dispose any material that has moldy residues, such as rags, paper, leaves, or
debris.

What can I save? What should I toss?
Substances that are porous and can trap molds, such as paper, rags, wallboard, and rotten wood
should be decontaminated and thrown out. Harder materials such as glass, plastic, or metal can
be kept after they are cleaned and disinfected. Ultimately, it is critical to remove the source
of moisture first, before beginning remedial action, since mold growth will return shortly if
an effected area becomes re-wetted.

Removal of Moldy Materials
After fixing the moisture source and removing excess moisture, the cleanup can begin:

Carpeting can be a difficult problem -- drying does not remove the dead spores. If there
is heavy mold, disposal of the carpet should be considered

Bag and discard the moldy substances

Allow the area to dry 2 or 3 days

If flooded, remove all sheetrock to at least 12 inches above the high water mark.
Visually inspect the wall interior and remove any other intrusive molds. (This step may have
to be carried out by a licensed contractor).

CAUTION: Spores are easily released when moldy material is dried out.

Soap Cleanup
Before disinfecting contaminated areas, clean the areas to remove as much of the mold (and
food it is growing on) as possible.

Wear gloves when doing this cleanup

Use a non-ammonia soap or detergent, or a commercial cleaner, in hot water, and scrub the
entire area affected by the mold

Use a stiff brush or cleaning pad on block walls or uneven surfaces

Rinse clean with water. A wet/dry vacuum is handy for this.

Disinfect Surfaces

Wear gloves when using disinfectants

After thorough cleaning and rinsing, disinfect the area with a solution of 10% household
bleach (e.g., 1½ cup bleach per gallon of water). Using bleach straight from the
bottle will not be more effective

Never mix bleach with Ammonia -the fumes are toxic

For spraying exterior large areas, a garden hose and nozzle can be used

When disinfecting a large structure, make sure the entire surface is wetted (floors,
joists, and posts)

Avoid excessive amounts of runoff or standing bleach

Let disinfecting areas dry naturally overnight -- this extended time is important to kill
all the mold.

CAUTION: Bleach fumes can irritate the
eyes, nose, and throat, and damage clothing and shoes. Make sure the working area is ventilated
well.

Can cleaning up be hazardous?
Yes. Exposure to mold can occur during the cleaning stage. Mold counts are typically 10 to
1000 times higher than background levels during the cleaning of mold damaged materials. Take
steps to protect your health during cleanup:

When handling or cleaning moldy materials, consider using a mask or respirator to protect
you from breathing airborne spores. Respirators can be purchased from hardware stores; select
one for particle removal (sometimes referred to as a N95 or TC-21C particulate respirator).
Respirators are not as effective removing bleach fumes, so minimize your exposure when using
bleach or other disinfectants.

Wear protective clothing that is easily cleaned or discarded

Use rubber gloves

Try cleaning a small test patch of mold first. If you feel that this adversely affected
your health, you should consider paying a licensed contractor or professional to carry out
the work

Ask family members or bystanders to leave areas when being cleaned.

Work over short time spans and rest in a fresh air location.

Air your house out well during after the work

CAUTION: Never use a gasoline engine
indoors (e.g. pressure washer, generator). You could expose yourself and your family to
dangerous carbon monoxide fumes.

Can air duct systems become contaminated with mold?
Yes. Air duct systems can become contaminated with mold. Duct systems can be constructed of
bare sheet metal, sheet metal with an exterior fibrous glass insulation, sheet metal with an
internal fibrous glass liner, or made entirely of fibrous glass. If your home's air duct
system has had water damage, first identify the type of air duct construction that you have.
Bare sheet metal systems, or sheet metal with exterior fibrous glass insulation, can be cleaned
and disinfected. If your system has sheet metal with an internal fibrous glass liner, or
are made entirely of fibrous glass, the ductwork normally will need to be removed and
discarded. Ductwork in difficult locations may have to be abandoned. If you have other
questions, contact an air duct cleaning professional, or licensed contractor.

After I've cleaned everything as thoroughly as possible, can I still have mold
odors?
Yes. It is possible that odors may persist. Continue to dry out the area and search for any
hidden areas of mold. If the area continues to smell musty, you may have to re-clean the area
again (follow the cleaning steps given in this sheet). Continue to dry and ventilate the area.
Don't replace flooring or begin rebuilding until the area has dried completely.

How can further damage to my home be prevented?
Check regularly for the following:

moisture condensation on windows

cracking of plasterboard

drywall tape loosening

wood warping

musty odor

If you see any of the above, seek out and take steps to eliminate the source of water
penetration, as quickly as possible.

Can ozone air cleaners help remove indoor mold, or reduce odor or pollution
levels?
Some air cleaners are designed to produce ozone. Ozone is a strong oxidizing agent used as a
disinfectant in water and sometimes to eliminate odors. However, ozone is a known lung
irritant.

Symptoms associated with exposure include cough, chest pain, and eye, nose, and throat
irritation. Ozone generators have been shown to generate indoor levels above the safe limit.
Furthermore, it has been demonstrated that ozone is not effective in controlling molds and
fungi, even at high concentrations far above safe health levels. Also, ozone may damage
materials in the home. For these reasons, the Mississippi State Department of Health
strongly recommends that you do not use an ozone air cleaner in any occupied residential
space.

Find out more

More information about the health effects of mold is available from the Centers for Disease Control and Prevention.